This invention relates to screeding of freshly-poured concrete, and in particular to a screed employing an initial roller for accurately treating the concrete surface as the screed proceeds along the concrete.
As set forth in my U.S. Pat. No. 4,838,730, the disclosure of which is incorporated herein by reference, precise tolerances are being demanded for concrete surfaces, therefore leading to development of concrete working apparatus which can produce finished concrete to meet those tolerances. In my U.S. Pat. No. 4,752,156, I describe a laser-guided screed as one type of apparatus which can meet such tolerances.
Concrete forms are also used to guide a screed to close tolerances. Typically, forms are placed on either side of an area which is to be covered with concrete, concrete is poured in that area, and a screed is drawn across that area to not only precisely level the concrete, but also, if vibratory, properly settle the aggregate in the concrete to assure that surface spalling does not occur.